The main objective of this project was to assess whether the levels of tin and aluminum, that are potentially added to food through preparation and storage, are sufficient to affect the utilization of essential nutrients. A 40-day study was conducted with 8 adult males to determine the effect of dietary tin (0.12 mg/day and 50 mg/day) on mineral utilization. Subjects lost significantly (p less than 0.01) more zinc in the feces and retained significantly (p less than 0.01) less zinc daily when fed the test diet (50 mg tin daily) rather than the control diet (0.12 mg tin daily). The level of tin in the control diet was typical of the amounts of tin in diets that contained only fresh and frozen foods. The amound of tin in the test diet was equivalent to the amount of tin that would be present in diets that contained four one-half cup servings of certain canned fruits and juices. A second 40-day metabolic study was conducted with 8 adult males to determine the effect of dietary aluminum (1 mg/day and 100 mg/day) on mineral utilization. Samples are now being analyzed.